As described in U.S. Pat. No. 6,580,034, which is incorporated by reference, certain demanding applications require miniaturized multi-wire cable assemblies. To avoid undesirably bulky cables when substantial numbers of conductors are required, very fine conductors are used. Coaxial wires having shielding are commonly used for the conductors to limit electrical noise and interference. In a coaxial wire, a central conductor is encapsulated by a dielectric sheath, the dielectric sheath is surrounded by a conductive shielding brade and the conductive shielding brade is encapsulated by an outer jacket. A bundle of such wires is surrounded by a conductive braided shield, and an outer protective sheath (see FIG. 4 of U.S. Pat. No. '034).
Some applications requiring many different conductors prefer that a cable be very flexible, supple, or “floppy.” In an application such as a cable for connection to a medical ultrasound transducer, a stiff cable with even moderate resistance to flexing can make ultrasound imaging difficult. However, with conventional approaches to protectively sheathing cables, the bundle of wires may be undesirably rigid.
Cable assemblies having a multitude of conductors may be time-consuming and expensive to assemble with other components. When individual wires are used in a bundle, one can not readily identify which wire end on a first end of a cable bundle corresponds to a selected wire at the second end of the cable bundle, requiring tedious continuity testing. Normally, the wire ends at the first end of the cable bundle are connected to individual pads on a connector or printed circuit board, the shields at the first end are connected to a common ground pad on the connector or printed circuit board, and the connector or board is connected to a test facility that energizes each wire, one-at-a-time, so that an assembler can connect the identified wire end to the appropriate connection on a second connector or board.
However, because the shields are connected to the same ground pad at the first end of the cable bundle, false identifications can occur where more than one center conductor is shorted to a conductive shield at the second end of the cable. Center conductors are often shorted to their own shields through the act of cutting the coax cables to a specified length which crushes the cable ends so that the center conductors and strands of the conductive shield can make contact. Clearing the shorts and/or re-terminating the cables is time consuming and can damage the coax cable.
The device disclosed herein allows for identification using individual shields before the coaxial cables are terminated and ganged together.